Apparatus for sharpening small drills



y 6, 1958 JIRO HAMAI 2,833,092 APPARATUS FOR SHARPENING SMALL DRILLS Filed Feb. 7, 1956 2 Sheets-Sheet 1.

W Mal/Irma y 6, 8 JIRO HAMAI 2,833,092

APPARQTUS FOR SHARPENING SMALL DRILL-S Filed Feb. '7, 1956 2 Sheets-Sheet 2 United States Patent APPARATUS FOR SHARPENING SMALL DRILLS .liro Hamai, Shinagawa-ku, Tokyo-to, Japan Application February 7, 1956, Serial No. 564,075

12 Claims. (Cl. 51-219) panying drawings which represent an embodiment of the invention.

In the drawings, Fig. 1' is a partially out front eleva-. tion of the apparatus of this invention, Fig. 2 is a side elevation of the same partially cut and Fig. 3 is a diagrammaticview of the essential parts thereof.

Withreference tothe drawings, 1 is a gimlet and 2' is a holder thereof, the latter being provided with a rackrod 3. 4 is a gear engaged with said rack-rod and is fitted on a shaft 5. 6 and ,7 are hands for grasping the end of a gimlet therebetween. 8 is a spring which is inserted between the said grasping hands so as to cause them to separate. 6' and 7 are holders of the said grasping hands. The end of each of the said holders comes in contact with the frame 9 and the rear end of the same is screwed in the frame 9 adjustably by means of a screw 10. 11 is a chock for causing the grasping hands 6 and 7 to grasp a gimlet therebetween when lifted and to release the said'gimlet when lowered. The other end of the said chock 11 is a handle 14 although it constitutes a movable frame 12 as a whole. The each side of the said movable frame 12 is supported by an adjusting member 13. 15 and 16 are rollers for receiving a Whetstone respectively and the holding members 15 and 16 are fitted with a screw 17 so as to enable the positions of the rollers 15 and 16 to beadjusted. 18 is a microscope for inspecting the sharpness of the gimlet end ground.

In operating the'apparatus of this invention, when the handle 14 is lifted, the movable frame 12 is moved around the adjusting member'lis as fulcrum and the chock 11 is lowered resulting in that the grasping members 6 and 7 are released by the elastic power of the spring 8. And when the handle 14 is lowered after a gimlet 1 is inserted into the upper end of the gimlet holder 2, the upper ends of the grasping members 6 and 7 approach to grasp a gimlet 1 therebetween. And the lower end of Whetstone (not shown) is put on the roller 15 or 16 and the top of the same is brought into contact with the gimlet edge by rotating the shaft through gear 4 and rack-rod 3 so as to cause the surface of the Whetstone to agree with the inclination of the gimlet edge. And then the Whetstone is put in reciprocating motion in the rotating direction of the roller so as to grind the gimlet edge. The opposite side of the gimlet edge is also equally ground with the surface of whetstone put on the roller 16. In this connection, it is to be noted that the inclination of the roller 15 or 16 is suitably adjusted according to the angle of gimlet edge etc. Such adjustment is carried out by manipulating the screw 17. The grinding degree can be inspected by the microscope.

In short, according to an apparatus of this invention, a small-sized gimlet which is easy to break can be ground safely during operation because such gimlet is grasped by a pair of. grasping hands and, further, the inclination of gimlet edge during. operation can be adjusted by regulating the position of gimlet by means of the gear 4 and rack-rod 3. Furthermore, according to this invention the grasping and release of a gimlet can be effected by the handle 14 causing the chock 11 to move up and down.

What I claim is:

1.An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held'with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and a release positionof said clamping portions; and guide means located transversely and longitudinally spaced from said clamping portions, said guide means having a guide face extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said guide means.

2. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movablesupport in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and a release position of said clamping portions; and guide means located transversely and longitudinally spaced from said clamping portions, said guide means having a guide face extending transversely of said longitudinal direction and adjustable to a plurality of angular positions in a plane parallel with said longitudinal direction, said guide face being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal directions while said Whetstone is in contact with the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the whetstone is manually moved while being guided by said guide means.

3. An apparatus for sharpening small drills, comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means including a pair of pivoted two-armed levers having clamping por tions at one end thereof spaced in said longitudinal direction from said support, said levers being spaced from each other at the opposite end thereof, spring means tend-1 ing to separate the respective clamping portions and to reduce the spacing of said other ends of said levers, said clamping portions being adapted to clamp the tip por- Patented May 6, 1958' tion of a drill held with its rear end in said movable support; first control means for setting said movablesupport in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and -a release position of said clamping portions, said second control means including w'e'dge means located between said spaced opposite ends of said levers formoving said clamping portions into clamping position by urging said opposite ends apart against the action of said spring means; and guide means located transversely and longitudinally spaced from said clamping portions, said guide means having a guide face extending transversely of said longitudinal directioniand being adapted to 'support an elongated Whetstone at predetermined angles with respect 'to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, whereby the t ip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said' guide means.

4. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal, direction of the drill; holding means having clamping portions spaced 'in said longitudinal direction from said support and being movably mounted in said base,'said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to saidbase, said first control means'including a rack bar attached to said movable support in longitudinal direction, and a turnable gear mounted for rotation in said base and engaging said rack; second control means for moving said holding means between a clamping, position and fa release position of said clamping portions; and guide means located transversely and longitudinally spaced from said clamping portions, said guide means having a guide face extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal andtransverse directions while said Whetstone is' in contact with the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said guide means.

5. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holdingmeans between a clamping position and a release position of said clamping portions; and guide means located transversely and longitudinally spaced from said clamping portions, said guide means including a' roller mounted on said base for rotation and having a guiding surface extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal andtransverse directions while said whetstonc is in contactwith the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said guide means.

6. An apparatus for shaipening small drills comprising, incombination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal'direction of the drill; holding means includ' ing a pair' of pivoted two-armed levers having clamping portions at one end thereof spaced in said longitudinal direction from said support,said levers being spaced from each other at the opposite end thereof, spring means tending to separate the respective clamping portions and to reduce the spacing of said other ends of said levers, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base, said first control means including a rack bar attached to said movable support in longitudinal direction, and a turnable gear mounted for rotation in said base and engaging said rack; second'coritrol means for moving said holding means between a clamping position and a release position of said clamping portions, said second control means including wedge means located between said spaced opposite ends of said levers for moving said clamping portions into clamping position by urging said opposite ends apart against the action of said spring means; and guide means located transversely and longitudinally spaced from said clamping portions, said guide means including a roller mounted ori said base for rotation and having a guiding surface'extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions While said whetstone is in contact with the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said guide means.

7. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and. movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and a release position of said clamping portions; and roller means located transversely and longitudinally spaced from said clamping portions, said roller means having an axis and a guide face extending transversely of said longitudinal direction and being adapted to. support an elongated whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said roller means.

8. An apparatus for sharpening small drills comprising, in combination, a base; a movable support'adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of adrill held with its rear end in said movable support; first control means 'for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping positions and a release position of said clamping portions; and two rollers located transversely and longitudinally spaced in opposite directions, respectively, from said clamping portions, said rollers having each an axis extending at a predetermined angle to said longitudinal and transverse directions, and guide surfaceextending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said rollers.

9. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and a release position of said clamping portions; a roller located transversely and longitudinally spaced from said clamping portions, said roller having an axis extending at a predetermined angle to said longitudinal and transverse directions, and a guide surface extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, and a bracket carrying said roller for rotation therein and being adjustable between a plurality of positions for adjusting the direction of said axis and of said guide surface, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said roller.

10. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and a release position of said clamping portions; and two rollers located transversely and longitudinally spaced in opposite directions, respectively, from said clamping portions, said rollers having each an axis extending at a predetermined angle to said longitudinal and transverse directions, and a guide surface extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, and two brackets mounted on said base, each of said brackets carrying one of said rollers for rotation therein and each being adjustable between a plurality of positions for adjusting the directions of said axes, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said rollers.

11. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means'for setting said movable support in a plurality of positions with respect to said base; second control means for moving said holding means between a clamping position and a release position of said clamping portions; a roller located transversely and longitudinally spaced from said clamping portions, said roller ing an axis extending at a predetermined angle to said longitudinal and transverse directions, and a guide surface extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, and a bracket carrying said roller for rotation therein and means for adjusting the position of said bracket with said axis of said roller moving in a plane parallel to saidlongitudinal direction between a plurality of positions for adjusting the direction of said axis and of said guide surface, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said roller.

12. An apparatus for sharpening small drills comprising, in combination, a base; a movable support adapted to receive the rear end of a twist drill and movable in longitudinal direction of the drill; holding means having clamping portions spaced in said longitudinal direction from said support and being movably mounted in said base, said clamping portions being adapted to clamp the tip portion of a drill held with its rear end in said movable support; first control means for setting said movable support in a plurality of positions with respect to said base; I

second control means for moving said holding means between a clamping position and a release position of said clamping portions; and two rollers located transversely and longitudinally spaced in opposite directions, respectively, from said clamping portions, said rollers having each an axis extending at a predetermined angle to said longitudinal and transverse directions, and a guide surface extending transversely of said longitudinal direction and being adapted to support an elongated Whetstone at predetermined angles with respect to said longitudinal and transverse directions while said Whetstone is in contact with the tip of said drill, and two brackets mounted on said base, each of said brackets carrying one of said rollers for rotation therein and means for independently adjusting each of said brackets, with the respective axes of said rollers moving in planes parallel to each other and to said longitudinal direction between a plurality of positions for adjusting the directions of said axes, whereby the tip of the drill is sharpened with the desired cutting and relief angles when the Whetstone is manually moved while being guided by said rollers.

References Cited in the file of this patent UNITED STATES PATENTS 2,429,057 Hanford Oct. 14, 1947 FOREIGN PATENTS 208,777 Germany Sept. 14, 1907 

